Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 18: Problem 36

Compare the temperature dependence of the conductivity for metals and intrinsic semiconductors. Briefly explain the difference in behavior.

Short Answer

Expert verified
Answer: The main difference in the temperature dependence of conductivity between metals and intrinsic semiconductors is that in metals, the conductivity decreases with increasing temperature, while in intrinsic semiconductors, the conductivity increases with increasing temperature. This difference is due to the fact that in metals, increasing temperature leads to more electron scattering due to lattice vibrations, whereas in intrinsic semiconductors, the increase in temperature results in a higher number of free charge carriers due to the creation of more electron-hole pairs.

Step by step solution

01

Conductivity in metals

In metals, the conductivity is mainly due to the movement of free electrons. When the temperature increases, the vibration amplitude of atoms in the metal lattice also increases. This causes more scattering of the free electrons, leading to a decrease in their average drift velocity, and ultimately a decrease in the conductivity. Therefore, the conductivity of metals generally decreases with increasing temperature.
02

Conductivity in intrinsic semiconductors

Intrinsic semiconductors are pure semiconductors with no impurities. Their conductivity is due to the presence of both free electrons and holes. At low temperatures, the number of free charge carriers (electrons and holes) is very small, resulting in low conductivity. However, as the temperature increases, the thermal energy helps to break more covalent bonds and creates more electron-hole pairs. This leads to an increase in the number of free charge carriers and, therefore, an increase in the conductivity. Hence, the conductivity of intrinsic semiconductors increases with increasing temperature.
03

Main difference in behavior

The main difference in the temperature dependence of the conductivity between metals and intrinsic semiconductors is that in metals, the conductivity decreases with increasing temperature, while in intrinsic semiconductors, the conductivity increases with increasing temperature. This difference can be attributed to the fact that in metals, increasing temperature leads to more electron scattering due to lattice vibrations, whereas in intrinsic semiconductors, the increase in temperature results in a higher number of free charge carriers due to the creation of more electron-hole pairs.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

(a) Using the data in Table \(18.1\), compute the resistance of a copper wire \(3 \mathrm{~mm}(0.12\) in.) in diameter and \(2 \mathrm{~m}(78.7 \mathrm{in}\).) long. (b) What would be the current flow if the potential drop across the ends of the wire is \(0.05 \mathrm{~V}\) ? (c) What is the current density? (d) What is the magnitude of the electric field across the ends of the wire?

Briefly describe electron and hole motions in a \(p-n\) junction for forward and reverse biases; then explain how these lead to rectification.

What are the two functions that a transistor may perform in an electronic circuit?

In your own words, explain the mechanism by which charge-storing capacity is increased by the insertion of a dielectric material within the plates of a capacitor.

Tin bronze has a composition of \(92 \mathrm{wt} \% \mathrm{Cu}\) and \(8 \mathrm{wt} \% \mathrm{Sn}\), and consists of two phases at room temperature: an \(\alpha\) phase, which is copper containing a very small amount of tin in solid solution, and an \(\epsilon\) phase, which consists of approximately 37 wt \(\%\) Sn. Compute the room temperature conductivity of this alloy given the following data: \begin{tabular}{ccc} \hline \multicolumn{2}{c}{ Electrical } \\ Phase & Resistivity \((\Omega \cdot m)\) & Density \(\left(g / c m^{5}\right)\) \\\ \hline\(\alpha\) & \(1.88 \times 10^{-8}\) & \(8.94\) \\ \(\epsilon\) & \(5.32 \times 10^{-7}\) & \(8.25\) \\ \hline \end{tabular}
See all solutions

Recommended explanations on Physics Textbooks

Fields in Physics

Read Explanation

Geometrical and Physical Optics

Read Explanation

Space Physics

Read Explanation

Atoms and Radioactivity

Read Explanation

Engineering Physics

Read Explanation

Turning Points in Physics

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free